Drilling machine



Patented Jan. 19, 1926.

UNITED STATES PATENT OFFICE.

DRILLING MACHINE.

Application filed September 4, 1920. Serial No. 408,282.

To all whom it may concern.

Be it known that l, GEORGE H. GILMAN, a citizen of the United States,and a resident of Boston, county of Suffolk, State of Massachusetts,have invented an Improvement in Drilling Machines, of which thefollowing description in connection with the accompanying drawings is aspecification, like characters on the drawings representing like parts.

My invention relates to drilling machines and particularly but notexclusively to a hammer rock drill.

My invention will be best understood from the following drawing andspecification of one specific embodiment of my invention submitted forillustrative purposes, while its scope will be more particularly pointedout in the appended claims.

In the drawings:

Figure 1 shows a longitudinal sectional elevation of the submittedembodiment of my invention.

Fig. 2 shows a partial section on the line 22 of Fig. 1.

Figs. 3 and 4 respectively show sections on the lines 33 and 4-4 of Fig.1; and

Fig. 5 shows a section on the line 5-5 of Fig. 2.

The submitted embodiment of my invention comprises a cylinder member 1provided with a large bore 2 and a reduced forward bore 3. Mounted forreciprocation in the cylinder is a piston having a large portion 41fitting the large bore 2 of the cylinder and an extension or hammer bar5 adapted to enter and fit in a fluid tight manner the reduced bore 3 ofthe cylinder. At the front end of the cylinder is rovided a chuckbushing 6 which carries t e shank of the drill steel 7. The rearward endof the cylinder is closed by the head plate 8 provided with a reducedportion 46 which enters the bore 2 of the cylinder. The head plate formsone section of a valve cage, the other section of which is provided bythe block *9, held in assembled relation, as tar as angular movement isconcerned, with the plate 8 by member beiandg means of dowels 10.

Carried by the cylinder member is a head block 11 and slida-bly mountedon the exterior cylindrical portion thereof is a sleeve 12 of the handlemember 13, the handle held in assembled relation with the'he block bymeans of the nipple 14, which is screw-threadedly secured to the headblock and extends through a slot 15 in the sleeve. The nipple 14 servesas aconnection for the airhose for supplying motive fluid for operatingthe machine.

For controlling the supply of motive fluid I provide a throttle valve 16which is adapted to be actuated by movement of the handle memberrelative to the head block. As the specific details of the throttlevalve and its operating mechanism form no part of my present 1nvent1on,the same will not be further described except in so far as necessary toexplain how they are coordinated with the other portions of my device.The head block is recessed to form a sleeve 17 secured by means of thescrew threads 18 to the rearward portion of the cylinder. At one side ofthe sleeve l provide a boss 19, which is perforatedto receive a bolt 20,the head 21 of which is cut away at 22 to conform with the exteriorsurface of the cylinder. When the sleeve is screwed into position, thebolt 20 may be tightened by means of the nut 23 to bind the surface 22of the bolt head against the surface of the cylinder and thereby preventrelative turning between the head block and cylinder.

At the bottom of the recess of the head block forming the sleeve isformed an annular passage 24 in communication with the passage 25adaptedto be placed in .communication with the source of motive fluid bymeans of "the throttle valve 16 in the manner hereinbefore referred to.As is clearl shown by Fig. 1, the sleeve of the head lock receives thevalve cage sections 8 and 9,'and when the sleeveis screwed into positionit clamps the o posed faces of the valve cage sections toget er, clampsthe opposite face of the section 8. to the rear face of the cylinder andclamps the opposite face of the section 9 to the face formed by thebottom of the recesses in the sleeve, in order to hold the parts firmlyin assembled relation and to form fluid tight joints between the facesmentioned.

The opposed faces of the valve cage sections 8 and 9 are recessed toform similar U-shaped passages 26, the recesses in the section 9 arebeing connected to the annular groove 24 in the head block by means ofpassages'27 communicating with the legs 28 of the recesses. Asillustrated in Figs. 1

lid

and 4-, the recesses are provided with upstanding annular portionsproviding the valve seats 29 30. Between the valve seats is adapted tovibrate a reed serving as controlling valve for supplying motive fluidfor actuating the piston. lhis reed is in the form of a steel spring 31,one end of which is secured to the valve cage. For so securing the reed,l have shown one side thereof provided with a raised portion 32,received in a recess in the valve section 8, the end of the reed beingadapted to be clamped between the opposed faces of the sections when thehead block is screwed on the cylinder. The portions of the sectionsadjacent the reed may be cut away to allow the same to vibrate and forthis purpose I have shown the valve cage section 8 cut away to form theslot 33, the opposed walls of which form a guide for the edges of thereed. For permitting the reed to seat I have shown the valve seat 29bevelled to conform to the shape which the surface of the reed assumeswhen in contact with the valve seat.

Leading from the seat 29 is a passage 34 for conducting motive fluid tothe rear end of the cylinder, and from the seat 30 leads a simlilatrpassage 35 which connects by means. of the passage 36 at right anglesthereto with a passage 37 extending through both valve cage sections andthe wall of the cylinder to the front end of the latter andcommunicating therewith through a port 33. It will thus be noted thatthe sections of the valve cage are recessed to provide a motive fluidchambpr which is connected to the source of motive fluid and to oppositeends of the cylinder and that when the sections are clamped together,said chamber is rendered fluid tight, and further that l have providedmeans carried by said sections which clamp one end of the reed betweenthe sections to provide means for securing the reed to one of them.

For exhausting the front end of the eviinder, the forward reduced boreis provided with an annular groove 39 which communicates by way of thepassage 40 with the atmosphere. When the hammer bar 5 withdraws from thebore3 of the cyl nder, the front end of the cylinder is connected to theatmosphere and when the hammer bar euters the reduced bore suchcommunication is interrupted. For exhausting the rear end of thecylinder it provide passages ll in communication with an intermediateportion of the cylinder by way of a slot 42. At their other ends thesepassages extend into the valve cage section 8 and open into a slot 4:3in communication with the annular groove dd formed in the head blocksleeve. The groove ll communicates with the atmosphere by means of apassage 45. When the rear end of the cylinder in its forward strokeuncovers the passage l2, the rear end to the U-shaped recess formed bythe valvecage sections, passes across the valve seat 3 and into thepassage 35 whence it finds its way to the front end of the cylinderthrough the passages 36, 37 and 38. At this time the rearward end of thecylinder is connected to the atmosphere through the groove 42, the

passages all, grooves a3 and dd passage to and under these conditionsthe reed is held firmly against the valve seat 29 and the piston movesrearwardly.

/V hen the piston moves rearwardly through part of its stroke it coversthe eshaust exit 42 from the rear of the cylinder and hence traps andcompresses motive iluid in the rear end of the cylinder, which tluidexerts sufficient pressure on the reed through the port 34 to cause thereedto move into contact with the opposite seat 30, this movement if thecompression is not sufficient to effect it being aided by the reductionof pressure in the ll-shaped passage of the valve cage when the hammerbar with draws from the reduced cylinder portion 3, thereby opening thepassage 37 to the atmosphere. When the valve moves to the positionopposite to that shown by Fig. 1, the air is admitted to the rear end ofthe cylinder through the port 3% to drive the piston forwardly, theexhaust from the front-end escaping through the reduced cylinder portion3 to the atmosphere ,by way of the grooves 39 and passage 40. W hen thehammer bar enters the reduced cylinder portion, the exhaust in theforward end is out ed and the motive fluid trapped in the cylinder iscompressed. The pressure of the compressed fluid is transmitted to thevalve through the port 38, passages 37, 36 and 35 and acts on the valveto exert a force tending to reverse it, which tendency will be increasedif insufficient to shift when the piston uncovers the groove 4:2 andthereby reduces the pressure in the valve cage by permitting the liveair then being admitted through the passa e 35 to the rear end of thecylinder to ex aust directly to the atmosphere. It will be ob= servedthat the motive fluid which is compressed in the front end of thecylinder acts on a much smaller area of the piston thanrthe motive fluidwhich is compressed in the rear end of the cylinder and further thatthere is a larger volume of motive fluid compressed on the rearwardstroke than on the forward stroke. This permits the piston on itsforward stroke to exert greater power than on its rearward stroke, whichresults in lessened rec roe

llll

and clamped vibration against the hand of the operator while deliveringa powerful blow to the tool.

Although I have described one specific embodiment of my invention forillustrative purposes it is to be understood that I am not limitedthereby to its specific mechanical details or to its proportion orarrangement of parts and that extensive deviations therefrom may be madewithout departing from the spirit of my invention.

Claims:

1. A percussive tool having in combination, a cylinder,a hammer pistonfor actuating a work performing tool carried at the forward end of saidcylinder, a valve cage closing the rearward end of said cylinder, ahandle' member having a socket receiving the end of said cylinder andclamping said valve cage to said cylinder, said valve cage havingtransverse sections with opposed peripheral annular faces in fluid tightcontact, a chamber formed in said cage and surrounded by said annularfaces, a passage leading from said handlev member to said chamber, avibratory reed removably clamped between said sections and extendingtransversely into said chamber, said reed at one end thereof having aprojection enterin a recess in one of said sections for positidning saidreed and for preventing slipa e ai d cylinder and entering said chamberthrough ports at opposite sides of the free end of said reed wherebysaid reed may control said ports.

2. A percussive tool having in combination, a cylinder, a piston, avalve cage carried by said cylinder, said valvecage having sections,means for clamping said sections together, a reed clamped at one endbetween said sections, said end of said reed having a transverseprojection, and a transverse recess in one of said sections receivingsaid projection.

3. In a percussive drill, a cylinder, a piston therein, a sectionalvalve cage, a vibratory reed positioned transversely of said cylinder, ahead block adapted to receive said valve cage, means for securing saidhead block to said cylinder adapted to clamp said reed between saidsections, and means for coordinately actuating said reed an said pistonincluding ports and passages formed in said section and in said cylinderfor conveying motive fluid controlled by said reed and by said piston.

l. In a percussive drill, a valve cage having opposed sections withannular faces in fluid tight contact, fluid passages formed in saidsections, a vibratory reed for controlling said assages carried by saidcage between said annular faces of said opposed sections, and means forpositioning and holding said reed in alignment with said ports.

thereof, and passages leading" from 5. In a percussive drill, acylinder, a piston therein, a valve cage having a plurality of sections,one of said sections having formed therein a recess, a passage leadingfrom said recess to one end of said cylinder, another section having apassage leading to the cylinder end opposite to the first mentionedcylinder end and communicating with said recess, seats about theconnections of said passages with said recess, a vibratory reed having aportion interposed between said seats and another portion between theopposed faces of said sections, said opposed faces having portions influid tight relation to prevent the passage of fluid from said recess tothe exterior of said cage, and means for clamping said sectionstogether.

6. In a percussive drill, a piston, members secured together and forminga fluid tight chamber therebetween, a vibratory reed extending throughsaid chamber, said reed being detachably clamped at one end thereofbetween said sections adjacent one side of said sections, said reed andone of said sections having means for positioning said reed relativelyto said sections and for preventing lateral movement of said reed, valveseats on opposite sides of said reed, a source of motive fluid, aconnection from said source to said chamber, and passages for conductingsaid motive fluid from said seats to actuate said hammer.

7. In a percussive drill, a piston. members secured together and forminga fluid tight chamber therebetween, a vibratory reed clamped betweensaid members and extending through said chamber, said reed having aprojecting portion at one end received by a recess in one of saidsections, valve seats on opposite sides of said reed, a source of motivefluid, a connection from said source to said chamber, and passages forconduct ing said motive fluid from said seats to actuate said hammer.

8. In a percussive drill, a cylinder, a piston, members secured togetherat one end of said cylinder and forming a fluid tight chambertherebetween, a vibratory reed, extending through said chambertransversely to said cylinder, said reed being at one end thereofclamped between said members, valve seats on opposite sides of saidreed, a source of motive fluid, a connection from said source to saidchamber, and passages for conducting said motive fluid from said seatsto actuate said hammer.

9. In a percussive drill, a cylinder, a piston therein, a member havinga passage connected to a source of motive fluid, a second and a thirdmember aligned with each other and with the first member, one of saidsecond and third members being recessed to provide a chamber, one ofsaid second and third members having a passage for connecting saidchamber with the passage of lid the first member, Vibratory reed in saidchamber and having one end thereof damped between said second and saidthird members, means for detachably connecting said first mentionedmember to said cylindeifor clamping said second and third memberstogether, and valve seats and passages arranged with said reed for theadmission of fluid alternately to the opposite ends of said cylinder.

10. in a neumatic hand hammer a cylinder, a free impact piston in saidcylinder, a head block closing the rearward end of said cylinder, saidhead block having transverse sections, a handle member engaging saidcylinder and holding the sections of said ease head block in assembledrelation therewith, a removable vibratory reed carried by said headblock transversely of said cylinder and being clamped at one end betweensaid sections, a source of motive fluid, ports and passages controlledby said vibratory reed for alternately admitting fluid from said sourceto opposite ends of said cylinder, and exhaust means for said cylinderdirectly controlled by said piston and arranged to be closed before thepiston reaches the end of its stroke in each direction.

In testimony whereof, I have signed my name to this specification.

enonen H. UKLMAN.

